In order to reduce the burden of the driving operation on a driver at the time of parking a vehicle, a variety of parking assistance techniques have been proposed and put into practical use. In “garage” parking where a vehicle is put into a parking space with its back first, the vehicle first moves forward beyond a parking space, stops, and then reverses into the parking space. In assisting this reverse parking, it is important to guide the vehicle appropriately to a reverse start position at which the vehicle stops moving forward and starts reversing. Japanese Patent No. 4414959 (Patent Document 1) discloses a technique where guide information marks G1 and G2 (see FIGS. 9 to 11 of Patent Document 1) serving as targets during forward movement are displayed on a monitor, and the vehicle is allowed to move forward so that such guide information marks fall within a frame indicator H (see the same figures), thereby guiding the vehicle to an appropriate reverse start position.